Liquid conductor heater



May 25, 1937. M. w. HANKS 2,081,537

LIQUID CONDUCTOR HEATER Filed Feb. l5, 1934 2 Sheets-Sheet l mag May 25,1937. M. w. HANKS 2,081,537V

LIQUID CONDUCTOR HEATER Filed Feb. 15, 1934 2 Sheets-Sheet 2 W l 20gPatented May 25, 1937 UNITED STATES PATENT GFFICE 7 Claims.

This invention relates to improvements in liquid conductor heaters ofthe type described in the United States Letters Patent of Marshall W.Hanks and Max Mason No. 1,683,071, dai-ed September 4, 1928, andMarshall W. Hanks No. 1,683,070, dated September 4, 1928, in which apair of spaced electrodes, connected in an electric circuit, are locatedin a vessel containing a measured quantity of water or other liquidconductor which is heated by the passage of current between theelectrodes with the result that the liquidconductor is eventuallyevaporated to substantial dryness, thereby giving the apparatus adefinite time period of operation. 'I'he principal object of the presentinvention is to provide an improved liquid vconductor heater of thistype in which a plurality of vessels are nested one within the otherwith parts of the vessels spaced apart and adapted to form theelectrodes be- 20 tween which an electric current passes through aliquid conductor contained in one of the vessels. A further object ofthe invention is to provide an improved liquid conductor heatercomprising a pair of vessels nested one Within the other, one of thevessels being adapted to contain material to be heated or cooked and theother vessel being adapted to contain a liquid conductor through whichan electric current passes between parts of the vessel which formelectrodes connected in an electric circuit. Still another object of theinvention is to provide a liquid conductor heater comprising a pluralityof metallic vessels nested one within the other and insulated from eachother by suitable enamel or the like, portions of adjacent vesselshaving opposed parts thereof uninsulated or provided with metalliccoatings or coverings and adapted to serve as electrodes between whichan electric current passes through a liquid conductor contained in oneof the vessels when the vessels are connected in an electric circuit. Afurther object of the invention is to provide a liquid conductor heatercomprising a vessel formed of bak-elite or other insulating material andhaving molded therein an electrode adapted to be connected in anelectric circuit. Another object of the invention is to provide a liquidconductor heater comprising a pair of vessels nested one within theother and having spaced metallic portions adapted to serve as electrodesbetween which an electric current passes through a liquid conductorcontained in the lower vessel, said vessels being provided with meansfor connecting them in an electric circuit only when they have theproper nested relation with each other. Other objects relate to variousfeatures of construction and arrangement which will appear more fullyhereinafter.

The nature of the invention will be understood from the followingspecification taken with the accompanying drawings, in which severalembodiments are illustrated. In the drawings,

Fig. 1 shows a vertical central section through a liquid conductorheater embodying the features of the present invention and comprising apair of nested vessels and a cover with electrical connections made toeach of the vessels for establishing circuit connections with the spacedbottom portions of the vessels which serve as electrodes;

Fig. 2 shows an enlarged vertical section taken through the upper edgeof one of the vessels shown in Fig. 1 and through an adjacent portion ofthe electrical terminal;

Fig. 3 shows an enlarged detail section taken on the line 3-3 of Fig. 1;

Fig. 4 shows a central vertical section taken through a liquid conductorheater similar to that illustrated in Fig. 1, except that portions ofthe metallic vessels serve directly as the electrodes between which thecurrent passes through a liquid conductor contained in the lower vessel;

Fig. 5 is a sectional view similar to that of Fig. 4, showing anotherform of construction in which the nested vessels are formed primarily ofinsulating material having spaced electrodes embedded in their bottomportions and having also embedded therein electrical conductors adaptedto be connected in an electrical circuit;

Fig. 6 is a central vertical section similar to that of Figs. 4 and 5,illustrating still another form of construction in which the lowervessel is provided with a special form of electrode which may bedesirable when the apparatus is used with certain liquid conductors;

Fig. 'l is a vertical section similar to those of Figs. 4, 5, and 6,illustrating still another form of construction of the electrodescarried by the bottom portions of the vessels;

Fig. 8 shows a top plan view of the upper electhe principles of thepresent invention are applied to a sterilizer.

The form of the invention illustrated in Figs. 1, 2, and 3 comprises apair of vessels I5 and I6. which are nested one within the other, and acover I1 which rests upon the upper vessel` I6. The lower vessel I5 isadapted to rest upon a table or other supportV I1 and to contain aquantity of water or other liquid conductor I8 through which an electriccurrent is adapted to pass from one vessel to the other when thesevessels are connected in an electric circuit. The lower vessel I5preferably has the central portion of its bottom I 5a concaved upwardlyas shown at I5b and the outer cylindrical wall of this vessel ispreferably contracted adjacent its upper edge as shown at I5, theextreme upper edge being turned outwardly to form an annular bead I5dupon which the upper vessel I6 rests. The vessel I6 is provided adjacentits upper part with an outwardly extending annular projection I6b whichforms a shoulder adapted to rest upon the bead I5d and to space thebottom I6a of the upper vessel from the bottom I5a of the lower vessel.The annular projection I6b is inclined upwardly and inwardly andterminates in an annular bead I6c which is adapted to form a support forthe cover iI1. This cover is provided with a dome-shaped central portionI1 terminating around its edge in an annular depressed portion I1b,around which there is formed, at a higher elevation, an outwardlyprojecting annular beaded portion I1c which rests upon/the bead I6 ofthe upper vessel. The central portion I1*l of the cover is provided witha handle I1d.

Both of the vessels I5 and I6 and the cover I1 A may be formed ofstainless steel or iron or other material adapted to be coated with aninsulating enamel or the like and all of these parts are preferablyconstructed as illustrated in Fig. 2, Where the lower vessel I5 is shownas comprising a central metal body I5e having an insulating coating ofenamel I5f or the like applied to both sides thereof. With thisconstruction, the vessels are electrically insulated from each other sothat no current passes between them through the liquid conductor I8except at those places where the metallic body portions of the vesselsmay be exposed to serve as electrodes. In the construction illustratedin Fig. 1, the bottom portions of the vessels are preferably providedwith separate electrode plates I9 and 20 which are secured to the bottomportions of the vessels I5 and I 6, respectively. These plates may beformed of copper, brass, or other material adapted to serve aselectrodes without substantial corrosion or disintegration during useand although they may be arranged to contact directly with the metallicportions of the bottom walls of the vessels from which the insulatingenamel is absent, the bottoms Iof the vessels are preferably coated andthey are connected thereto by metallic fastening members. The lowerelectrode I9 has the central portion thereof punched downwardly to forma sleeve I9a which is internally threaded for engagement with a stud 2lwhich has its head welded or otherwise secured to the bottom wall of thevessel I5 within a depression |58' which is formed in the bottom wall.When the electrode I9 is screwed downwardly onto the stud 2l, its

lower surface contacts with the insulated upper i surface of the bottomwall I5, and an electrical connection with the metallic vessel isestablished through the stud. In a similar way, the electrode plate 20has its central portion punched upward- 1y to form a sleeve 20* which isinternally threaded [for engagement with a stud 22 which is welded orotherwise secured to the upwardly projected portion I6l of the bottomwall of the vessel I6. When the electrode 20 is applied to the stud 22,as shown in Fig. 1, the upper surface of the electrode contacts directlywith the enameled surface of the vessel I6 and an electrical connectionis established with that vessel through the stud. The metallic portionsof the two vessels are connected to the opposite terminals of anelectric circuit, as hereinafter described.

The vessel I5 is provided with an outwardly projecting handle 23 whichcomprises a metallic member 24 secured to the metallic body of thevessel I5 and an outer insulating cover 25. The metallic portion 24 ofthe handle is in the form of a sheet metal member having its lateraledges turned downwardly and inwardly to provide beads 24a, as shown inFig. 3, which give strength and rigidity to the structure. The inner endof the member 24 is welded or otherwise secured to the metallic body I5eof the vessel, as shown in Fig. 2, and at its other end, the member' 24has secured thereto, between the beads 24, a projecting terminal 26. Thevessel I6 is similarly provided with a handle 21 which is made up of aninner metallic member 28, having the same cross-sectional form as themember 24 and having its inner end welded or otherwise secured to themetallic body portion of the vessel I6. 'I'he member 28 is similar incross-section to the inember 24, having beaded portions 28 along itsedges, and a metallic terminal 29 is welded or otherwise secured to theouter end thereof to extend parallel to the terminal 26. The upperhandle 21 comprises an outer insulating portion 30 which is mounted onthe member 23. The members 25 and 30 extend substantially throughout thelength of the members 24 and 28, which are enclosed by them, and, attheir outer ends, these insulating members are provided with housingportions 25EL and 30a which are U-shaped in cross-section, as shown inFig. 3, with their openings directed toward each other so that they forma composite socket in which the terminals 26 and 29 are located.

When the vessel I6 is in nested relationship to the vessel I5, the twohandles 23 and 21 extend parallel and in proximity to each other so thatthe terminals 26 and 29 may then be caused to engage the tubularconducting members 3| which are embedded in an insulating plug 32 inwhich the members 3i are connected to supply conductors 33 leading froma source of electrical current. The plug ts within the composite socketformed by the U-shaped members 25 and 3|! on the ends of the handles andin this way a connection may be quickly and easily made with the supplycircuit by which the electrical heating device is to be operated. Itwillbe apparent that the plug 32 and the conductors carried thereby maybe brought into connection with the terminals 26 and 29 of both of thevessels I5 and I6 only when these Vessels are in proper nestedrelationship with each other and with the handle 21 arranged to extendparallel to and above the handle 23, thus insuring against the operationof the device unless it has been properly arranged -and prepared foruse. Assuming that the device illustrated in Fig. 1 is to be employedfor cooking material placed in the vessel I6, a quantity of water isfirst placed in the vessel I5, before brirging the vessel I6 into nestedrelationship with the vessel I5, whereupon the I to the material to becooked. Unless the circuit connection is interrupted, this operationcontinues until the liquid conductor I6 in the vessel I5 disappears byevaporation, whereupon the velectrical connection between the ele'ctrodeplates I9 and 20 is broken and lthe operation of the apparatus isterminated. The cooking apparatus may thus have 'a definitepredetermined time period of operation if a measured quantity of theliquid conductor I8 is initially placed in the vessel I5.

In Fig. 4, there is illustrated a modification of the invention in whichtwo vessels 35 and 36 are nested one within the other in the same manneras the vessels I5 and I6 and are provided adjacent their upper edgeswith handles similar to those illustrated in Fig. 1, by which themetallic portions of the vessels may be connected to opposite. sides ofan electric circuit. In this modiiied construction, the vessel 35comprises an inner metallic body portion 35a which is provided on itsouter side with an insulating coating of enamel or other material 35band on its inner side with a similar coating of insulating material 35.The vessel 36 is of similar construction, being made up of an innermetallic vessel 36 provided with an outer insulating covering 36b and aninner insulating covering 36. In the bottom of the vessel 35, theinsulating lining 35c is omitted over a central area of considerablesize, as shown at 35d, thus leaving an exposed portion 35 of themetallic vessel 35iL which serves as an electrode and which may becircular in form. The bottom portion of the upper vessel 36 is soconstructed that the insulating cover- .ing 36b is omitted on the bottomof the vessel,

as shown at 36d, over an area which is the same as the area of theexposed portion of the metallic body 35 of the metallic portion 35a ofthe lower vessel, thus providing an electrode 36 which is locatedopposite to the electrode 35 so that when the two vessels are connectedin an electric circuit, current will pass from one electrode to theother through the liquid conductor 31 which is contained in the lowervessel 36. This construction is capable of use where it is not desiredto provide the additional electrode plates shown in Fig. 1 and willfunction satisfactorily, particularly if the exposed portions 35 and 36of the metallic vessels be coated with conducting material to preventcorrosion or disintegration thereof.

Instead of making up the nested vessels of inner metal vessels coveredover substantially their entire areas with insulating material, it maybe desirable to form the vessels almost entirely of insulating materialwith the electrodes and their connections embedded therein, as shown inFig. 5. In this construction, an outer vessel 4I and an inner vessel 42are nested one within the other, in substantially the manner illustratedin Fig. l, and each of these vessels is formed of porcelain, bakelite,or other insulating material. When the vessels are nested one within theother, the bottom of the vessel 42 is spaced upwardly from the bottom ofthe vessel 4I, leaving a space which is occupied by the liquid conductor43 which partially illls the lower vessel. The central portion of thebottom wall 4I'L of the vessel 4I is provided with an electrode 44 inthe form of a metal plate which is embedded in the insulating materialof the bottom wall with its upper surface exposed to direct contact withthe liquid conductor 43. The bottom 4I.L of the upper vessel 42 hasanother electrode 45 of conducting material embedded therein and exposedon its under side to the liquid conductor 43 so that when the electrodesare connected in an electric circuit, current will pass between themthrough the liquid conductor. For the purpose of establishing aconnection with the circuit, the electrode 44 is connected to aconductor 46 and the electrode 45 is connected to a conductor 41. Theseconductors 46 and 41 may be comparatively narrow and they are embeddedin the walls of the vessels 4I and 42, respectively, with their upperends terminating adjacent the upper edges of these vessels where theyare connected to the conducting portions of handles, similar to thoseshown in Fig. 1, whereby a connection may be elsltiblished with theterminals of a supply circ In Fig. 6 there is shown another form orconstruction comprising an outer vessel 5I and an inner vessel 52 whichare nested one within the other in the manner heretofore described, theouter vessel being adapted to contain a liquid conductor 53. `\The uppervessel 52 has an exposed electro'e "S formed as a part of or attached toits bott Prn wall and connected in the circuit inthe manner shown inFig. 2, or in the manner illustrated in Fig. 5. The lower vessel 5I isprovided with an opposed metallic electrode 55 which is constructed inthe form of a cone having an apex provided with a threaded sleeve 55adapted for engagement with a stud 56 which is welded or otherwisesecured to the metallic portion of the underlying bottom wall 5Ia of thevessel. 'I'he metallic portion 'of the bottom wall 5I may be connectedto one branch of a circuit in the manner heretofore described. Thisconstruction may be of peculiar advantage in employing a body of wateror other liquid conductor 53 whose characteristics are such that theapparatus may not operate with the highest degree of eiciency whenemploying parallel ilat electrodes. One advantage of the cone-shapedelectrode is that it allows a ready escape of bubbles from the regionbetween the electrodes.

In Figs. 7, 8, and 9 of the drawings there is illustrated another formof the invention which is like that illustrated in Fig. l except thatthe vessels 51 and 56 which are nested one within the other are providedwith modified forms of electrodes. In this arrangement, the outer vessel51 has a bottom wall 51 provided with a metallic portion which contactsdirectly with an electrode plate 59 having a threaded engagement with astud 60 which is secured to the central depressed portion 51h of thebottom wall. The metallic portion of the vessel 51 being connected in anelectric circuit, a connection is established through the vessel withthe electrode 59 and current may then pass from this electrode tianother electrode 6I which is secured upon the bottom of the vessel 548.The electrode 6I is in the form of a metallic plate having a centralsleeve 6Ia which threadedly engages a stud 62 attached to the bottom ofthe vessel 58 and thc plate 6I is uted radially from the center withportions of the flutes or convolutions inclined upwardly to coincidewith the surface of a marginal cone having its outer edge engaging thebottom of the vessel 56. The lowermost edges of the utes or convolutions6lb which are thus formed in the electrode plate extend horizontallyparallel to the lower electrode 59. This :crm of construction of theupper electrode is adapted to permit a more ready escape of bubbles fromthe region between the electrodes than would occur if both electrodeswere flat. In this construction, the vessels are preferably made up ofinner metallic portions having outer and inner coverings of insulatingenamel or the like and the metal portions of these vessels are adaptedto be connected in an electric circuit in the manner heretoforedescribed.

In Fig. 10 there is illustrated the adaptation of the present inventionto apparatus intended primarlly for the making of coffee and thisimprovement embodies many of the advantages of the construction which isdescribed and claimed in my co-pending application Serial No. 431,713,led February 27, 1930. v'I'his apparatus comprises a series of vesselsnested one within the other, including an upper vessel adapted tocontain water, a second vessel 66 which contains the vessel 65 and isspaced downwardly and outwardly therefrom, a third vessel 61 whichcontains and supports the vessel 66 and which is adapted to containcoffee grounds, and a lower vessel 68 which is adapted to support thevessel 61 and which receives the liquid coffee. The upper vessel 65 isadapted to contain a body of water 69, when the apparatus is initiallystarted in operation, and its bottom wall 65"l is preferably constructedin the form of an inverted cone having an aperture 65b at its centerthrough which. the water may flow downwardly. This bottom wall 65a mayitself serve as an electrode or it may be provided on its under sidewith a separate electrode plate 18 which contacts directly with themetallic body portion of the vessel 65. The vessel 65 may be providedadjacent its upper edge with an outwardly extending annular enlargement65c which rests upon a bead 66l formed around the edge of the next lowervessel 66, this outwardly projecting portion 65c terminating at itsupper edge in an annular bead 65d, or the bottom 65a of the vessel 65may rest directly on the annular ledge 66b formed around the bottom ofthe vessel 66. At one side of the vessel 65, the annular enlargement 65cis connected with a handle 1| which is of the form illustrated in Fig.1, being provided with a metallic terminal 12 which is adapted to engagethe plug attached to conductors leading from a source ofelectriccurrent. The second vessel 66 may be provided with anenlargement 66, adjacent the bead 66d, which rests upon the annular bead61d formed around the upper edge.

of the vessel 61, or the bottom of the vessel 66 may rest directly onthe coffee grounds in the vessel 61 and thus pack the grounds throughwhich the water passes. The bottom of the vessel 66 is provided with aportion 66a which is constructed in the form of an inverted cone similarin form to the bottom wall 65a of the vessel 65. The portion 66EL isoffset downwardly from an annular ledge 66h which is united with theouter cylindrical Wall of the vessel 66 and, between the parts 66a and66b there is provided a substantially cylindrical circular portion 66ehaving a series of small apertures 66f. formed therein. The metallicportion of the part 66a of the bottom wallmay itself serve as anelectrode but in the construction shown in Fig. 10 there is provided aseparate cone-shaped electrode plate 13 which is attached to the upperside of the part 661.`\-'The annular enlargement 66c of the vessel 66 isprovided with a projecting handle 14, similar to the handle 23 shown inFig. 1, and having a terminal 15 which may be connected in an electriccircuit. When this circuit is completed, current may flow to theelectrode plate 13 through the wall of the vessel 66 and then upwardlyto the cone-shaped electrode plate 10 through a portion of the water 68which will have flowed downwardly into the space between the electrodesthrough the aperture 65".

The water which is heated by the passage of current between theelectrodes 18 and 13 ows outwardly through the small hole 66t and dripsdownwardly through thecoffee grounds 11 which are contained in thedepressed bottom 613L of the vessel 61. The central portion of thisbottom wall is provided with a series of perforations 61b and the liquidcoffee which is formed by the passage of the hot water through thecoffee grounds drips downwardly through these apertures 61b into thebottom vessel 68. The vessel 68 is adapted to rest upon a table or othersupport 18 and it is provided around its upper edge with an annularflange 68 which forms a seat for the vessel 61. With this novelarrangement, a small quantity of cold water, for example, a singlecupful, may be poured into the upper vessel 65 and, the terminals 12 and15 having pref viously been connected in a circuit, this water, uponiiowing downwardly through the hole 65b in the upper vessel, will causea current to flow between the electrodes 18and 13, with the result thatthe water between the electrodes is heated and ows outwardly through theapertures 661` and thence downwardly through the coffee grounds, thusproducing a single cupful of liquid coffee in a short interval of time.It will be apparent that this improvement may be applied to coffeemaking apparatus of varying capacity and that the vessels 65 and 66, andtheir electrodes, may be constructed and mounted in any of the waysheretofore illustrated in connection with the other forms of theinvention.

In Fig. 1l, there is shown a further modification of the inventionadapted for use as a sterilizer. The construction is the same as thatshown in Fig. 1, except that openings are provided for admitting steamfrom the outer vessel to the inner vessel which serves as thesterilizing chamber. As illustrated, the sterilizer comprises an outervessel 80 and an inner telescoping vessel 8l which is supported thereby,for example, by providing the inner vessel with an annular portion 8lbwhich rests upon the upper edge of the outer vessel. A cover 82 rests onthe inner vessel and thus closes the upper end of the sterilizingchamber 83 in which the objects to be sterilized are placed. The twovessels 8l) and 8| are formed of suitable metal, such as stainlesssteel, and are provided on their inner and outer sides With insulatingcoatings, the metallic portions of these vessels being connected to theterminals of an electric circuit through handles 84 and a plug 85, as inthe form shown in Fig. 1. 'I'he insulating coatings are removed fromopposed portions of the bottom walls of the vessels and the exposedmetal portions of the vessels may serve as electrodes or they maycontact directly with separate parallel electrode plates 86 and 81. Theouter vessel 88 is adapted to contain a body of water or othervaporizable fluid 88 which establishes a y connection between theelectrodes 86 and 61 and is heated and vaporized by the passage ofcurrent therethrough. To admit the steam or vapor thus produced to thesterilizing chamber 83, a series of holes BIC may be provided in thebottom 8la of the inner vessel around the electrode 81 or a series ofholes 8 Id may be provided in the annular Wall of this vessel above thelevel of the water 88.

Although several forms of the invention have been shown and described byWay of illustration, it will be understood that it may be constructed invarious other embodiments within the scope of the appended claims.

I claim:

1. 'I'he combination in a liquid conductor heater, of a pair of vesselsnested one within the other and having metallic portions spaced apart`to serve as electrodes, one of said vessels being adapted to contain aliquid conductor for connecting said electrodes, means for connectingsaid vessel vin an electric circuit, and means for preventing theoperation of said connecting means when said Vessels are not in propernested relation to each other.

2. The combination in a liquid conductor heater, of a pair of vesselsnested one within the other and having metallic portions spaced apart toserve as electrodes, one of said vessels being adapted to contain aliquid conductor for connecting said electrodes, a pair of conductingmembers extending normally in parallel relation and each connected toone of said vessels, and means engaging said conducting members whenthey are in said parallel relationship for connecting them to theterminals of an electric circuit.

3. 'I'he combination in a liquid conductor heater, of a pair of vesselsnested one within the other and having metallic portions spaced apart toserve. as electrodes, one of said vessels being adapted to contain aliquid conductor for connecting said electrodes, a pair of insulatinghan- 40 dles each carried by one of said vessels and adapted to extendin parallel relationship one above the other, conducting membersattached to said vessels and extending through said handles, and meansengaging said conducting mem- 45 bers for connecting them to theterminals of an extending outwardly therefrom in normal parallelrelationship, insulating members enclosing said conducting members andhaving registering sockets at their outer ends, and-an insulating plugengaging said sockets and having means for connecting said conductingmembers to the terminals of an electric circuit.

5. The combination in coffee making apparatus, of a vessel adapted tocontain liquid coffee, a second vessel supported by said rst namedvessel and having a perforated bottom adapted to support coffee grounds,a third vessel nested within said second named vessel and having ametallic portion adapted to serve as an electrode with perforationstherethrough adjacent said electrode portion, a fourth vessel nestedwithin said third named vessel and having a metallic portion adapted toserve as an electrode spaced from said electrode portion of said thirdnamed vessel, said fourth vessel being adapted to contain water andhaving a perforation through which said water iiows to the space betweensaid iirst named and second named electrode portions, and means forconnecting said third named vessel and said fourth named vessel to theopposite terminals of an electric circuit.

6. The combination in coiee making apparatus, of a plurality of vesselsnested one within the other, two of said vessels being of metalinsulated from each other and provided with means for connecting them`to the terminals of an electric circuit, said insulated vessels beingprovided with exposed metal parts serving as spaced electrodes, one ofsaid vessels being adapted to contain Water and to admit said watergradually to the space between said electrodes, another of said vesselsbeing adapted to contain coffee grounds and to receive the heated waterfrom said electrodes.

7. The combination in coffee making apparatus, of a plurality of vesselsnested one within the other, two of said vessels being of metalinsulated from each other and provided with means for connecting them tothe terminals of an electric circuit, said insulated vessels beingprovided with exposed metal parts serving as spaced electrodes, one ofsaid vessels being adapted to contain Water and to admit said watergradually to the space between said electrodes, another of said vesselsbeing adapted to contain coffee grounds and to receive the heated waterfrom said electrodes, another vessel being adapted to collect the liquidcoffee formed by the passage of said heated coffee through said coffeegrounds.

MARSHALL W. HANKS.

